The present invention relates generally to manual hand tool for sanding and finishing the surface of a workpiece and, more specifically, to a tool which allows quick exchange of sanding and finishing materials.
Hand sanders are used in conjunction with sandpaper and other materials for purposes of removing paint, rust and other undesirable surfaces. They are also used to finish or polish the surfaces of items constructed of metal, wood, plastics and various other materials. One very common way to sand a workpiece is to use a sanding block. Most prior art manual sanding blocks include a working surface over which the sandpaper or other material is wrapped. The block may also include a handle to facilitate gripping the block during use. Manual sanders, ie., non-mechanized sanders, are particularly utilized when maximum control over sanding pressure is desired, such as in model-making, doll-making and other hobbies and crafts. Manual sanders also provide a less expensive alternative to mechanized sanders.
Manual sanders often are constructed to maximize available working surface area and result in working surfaces of two to four times the size of the user""s hand. It is important to note, however, that since manual sanders rely on the force or pressure from the user""s hand, much of the larger working surface area is not efficiently utilized because the hand does not reach all areas of the working surface. The efficient use of primary working materials such as sandpaper, polishing sheets or buffing cloths directly impact user costs. Sections of working material that are not used during sanding or finishing are simply wasted if the material cannot be rotated to correspond to the pressure points of the sander. If the working material is rotated, the user must use valuable time to adjust the working material to maximize the use of surface area of the material. Alternatively, the user must change the working material more often than is necessary and waste unused material.
Manual sanding blocks often result in fatigue when used over extended periods because the user must place his or her hands in unnatural, uncomfortable positions to use the sander or the user must use both hands to effectively control the large surface area of the sander. One example of such a manual hand sander design may be found by reference to U.S. Pat. No. 5,054,248 to Thayer. In the Thayer design, the leading ends of the sander extend from the handle in different lengths and thicknesses. In order to effectively use the extended ends of the sander, one hand must be used to hold the sander while the other hand is used to apply pressure to the extended ends. Such designs are especially difficult to use by woman or children who tend to have smaller or weaker hands or by people who suffer from arthritis or other limiting conditions.
In an attempt to overcome these deficiencies, manual sanders which minimize the time needed to change working material have been proposed. Examples of such devices may be found by reference to U.S. Pat. No. 2,809,476 to Bourdunis, U.S. Pat. No. 3,123,947 to Rawley and U.S. Pat. No. 4,944,128 to Reiter. Such designs utilize spring loaded clamps to hold sheets or strips of working materials taut against the body of the sander. These designs do not, however, fully utilize a sheet or strip of working material but merely operate to change sheets more quickly than other designs. Further, if a different grade of material is required, the entire roll or sheet of working material must be removed from the spring loaded device and replaced. If the user must switch between grades of material multiple times, the process clearly becomes time consuming.
However, in light of the present invention, the aforementioned designs are deficient in that they do not, in combination, fully utilize working materials and provide quick and easy interchange of work materials. Further, extended use of prior art sanders results in increased hand and body fatigue.
Briefly described, in a preferred embodiment, the present invention overcomes the above-mentioned disadvantages by providing a hand-held manual sander that utilizes a natural, comfortable hand position which encompasses the entire sander within the hand of the user and, in effect, makes the sander an extension of the user""s hand. Because the working surface area is not extended beyond the control of the hand, waste of working material is minimized. The present invention, therefore, provides a comfortable, secure grip and maximum control over the force and pressure exerted on the workpiece. The present invention reduces fatigue during use since the hand is placed in a natural, unextended position. This feature is especially useful for people with small or weak hands. Further, the present invention allows the user to quickly change working materials to suit the needs of the workpiece.
Generally, the present invention, in the preferred embodiment, comprises a sander body, a hand grip, a mounting plate and a working surface. More specifically, the sander body includes a generally cylindrically shaped member designed to reduce hand fatigue during extended use of the sander. The hand grip is adapted to the size of a palm for a single handed grip around the sander. A finger recess around the periphery of the hand grip portion is designed to further facilitate one-handed use. The mounting plate extends from the sander body. The working surface is associated with the bottom of the mounting plate. The outer periphery of the mounting plate substantially defines the size of the working surface and, therefore, the size of working materials such as sandpaper.
The working surface consists of hook type materials of hook and loop mechanical attachment systems. The working surface is bonded to the base of the mounting portion by adhesion such as cement or pressure sensitive adhesive. A circular sheet of working material is releaseably attached to the working surface of the sander body. The selection of products for the working materials may consist of but is not necessarily limited to a variety of surface preparation and finishing materials having attaching surfaces adapted to one or more hook and loop style interlocking surface devices.
A feature and advantage of the present invention is to provide a new and improved hand-held manual sander which permits the quick and easy interchange of working materials such as sanding, finishing or polishing sheets.
Another feature and advantage of the present invention is to provide a new and improved hand-held manual sander which minimizes discomfort to the user when used over extended periods of time.
Another feature and advantage of the present invention is to provide a new and improved hand-held manual sander which accommodates a small or weak hand of a user.
Still another feature and advantage of the present invention is to provide a new and improved hand-held manual sander which maximizes the use of the entire surface of the sheet of the working material.
Yet another feature and advantage of the present invention is to provide a new and improved hand-held manual sander which increases the efficiency of the sander by aligning the forces of the hand directly to the surface of the workpiece.
Still another feature and advantage of the present invention is to provide a new and improved hand-held manual sander which may be easily manufactured.
A further feature and advantage of the present invention is to provide a new and improved hand-held manual sander which may be produced at a low cost of manufacture with regard to materials and labor, thereby making the manual sander economically available to the buying public.